Power line communication (PLC) technology employs power lines as transmission medium to convert analog or digital signals into high-frequency signals by means of the carriers, achieving long-distance transmission of the signals via the power lines, which has the advantages of long distance transmission, high channel reliability, good security confidentiality, less investment with quick returns, and capable of being synchronized with the power grid construction, etc.
However, in the PLC-based applications, due to the large number of devices, multiple power lines are usually provided to transmit high-frequency signals, and the multiple power lines are disposed in the same wire conduit to simplify the field wiring. The coupling capacitance formed between different power lines that are closed to each other will provide a wrong transmission path for the PLC-based high frequency signals, thereby incurring crosstalk among the signals sent to different devices, resulting in the device executing misoperation based on erroneous high frequency signals, which will seriously affect the safety of the electrical equipment.